Deposits which contain radioactive elements are often formed in the cooling systems of nuclear reactors. In order to safely maintain and repair the cooling system, it is necessary to remove these radioactive deposits. This can be accomplished, for example, by using an oxidizing solution of an alkali permanganate followed by a decontamination solution of oxalic acid, citric acid, and ethylenediamine tetraacetic acid (EDTA). These solutions solubilize the radioactive metal ions and the other ions in the deposit. The solutions are circulated between the cooling system and ion exchange resins which then remove the ions from the solution.
While many effective decontamination and oxidizing solutions have been found, there is always a need for improved solutions which remove the deposits more readily, are less expensive, or create less waste volume (e.g., spent ion exchange resins). Also, because reactor downtime for removing the deposits is extremely expensive, solutions which can clean the cooling systems more rapidly can save large amounts of money.
Another problem in the nuclear industry is the disposal of steam generators at the end of their useful life. Because the steam generators are highly radioactive, it is necessary to construct an expensive containment building around them to prevent the escape of radiation. Decontamination solutions have not been effective in reducing the radioactivity of these generators to the level required to eliminate the need for a containment building.
Still another problem in the nuclear industry occurs in the mining, treatment/reprocessing, and fabrication of nuclear fuel. Not only does equipment become radioactively contaminated, but the contaminates include uranium and plutonium, which could be used in making fuel if they could be readily and inexpensively recovered from the contaminated equipment.